Understanding the influence of the captive environment on the well-being of captive primates is critical for guiding management decisions and facility design. This project contributes to our understanding of the behavioral consequences of environmental variations both in and outside the primary enclosure. During the past year, multiple measures of behavioral well-being were used to accomplish the following 1) a comparison of two types of indoor housing common to biomedical research on chimpanzees, 2) an analysis of the influence of calls and displays produced by neighboring groups on the agonistic behavior, 3) an assessment of the relation between displacement activities and anxiety, and 4) a detailed analysis of regurgitation and reingestion, including sex differences, eliciting factors, and the influence of diet. Findings have demonstrated that chimpanzees housed in pairs and trios show fewer signs of tension, anxiety, and aggressiveness than singly-housed chimpanzees, but that the presence of one or two cagemates is not sufficient for ameliorating all the behavioral deficits found in singly-housed chimpanzees. Other findings in this project show a positive correlation between intragroup agonism and the vocalizations of neighboring groups. This effect is congruous with behavioral patterns observed in the wild. It is therefore considered an expression of species-typical behavior as opposed to an artifact of captivity, but is nonetheless highly relevant to captive management. In addition, employing neighbor vocalizations as a tool for examining the relationship between anxiety and displacement activities in other primates suggests that rough scratching is the most reliable indicator of anxiety in chimpanzees. Lastly, this project generated information critical for generating effective strategies for ameliorating regurgitation and reingestion in chimpanzees, including increasing meal frequency and providing consistently available edible material. These findings have been presented in abstract form at scientific meetings, including the International Primatological Society and American Society of Primatologists, and have been published in peer-reviewed journals. This project contributes significantly to the reduction of behaviors detrimental to psychological well-being, the refinement of behavioral markers of psychological well-being and our ability to tailor the captive environment to meet the needs of chimpanzees.